Div out of place, help

Would one of you who has some experience offer me some assistance here.
http://aljones.us/630904vad.php (since I repeat major parts of every page, the php is just a lot of includes)
I end up with either of two situations, the one you see here where the content div is forced to the end of the navigation div by a clear both -or- the content div stairsteps each of the diary entries where the text of the previous entry is shorter than the image.
The third column (float right) in green is a space holder for google adds.
Safe to say, what I want to see is the way the diary is layed out now, but immediately under the top nav bar.
Any help???
//al

Changed the css so that the content div is position: absolute
now as I go from page to page ( letter to diary to letter, etc ) the page jumps left and right. Same CSS, same code ( most of it is php includes so I know it's the same! ) don't understand why it would shift left / right?
Yes, I realize the colours are really bad on *my* navigation but I'll worry about the small stuff when I get it to lay out right.
Suggestions anyone?